A Gram-negative, non-spore-forming, yellow-pigmented bacterium, strain N4(T), was isolated from a nickel-complexed cyanide-degrading bioreactor and subjected to a polyphasic taxonomic study. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain N4(T) is affiliated to the genus Chryseobacterium of the family Flavobacteriaceae. The levels of 16S rRNA gene sequence similarity between strain N4(T) and the type strains of all known Chryseobacterium species were 93.2-95.8 %, suggesting that strain N4(T) represents a novel species within the genus Chryseobacterium. The strain contained iso-C(15 : 0) and summed feature 4 as the major fatty acids and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 38.2 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain N4(T) represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium caeni sp. nov. is proposed. The type strain is N4(T) (=KCTC 12506(T)=CCBAU 10201(T)=DSM 17710(T)).